TAMPA, Fla. — As spring training winds down, the Yankees are preparing to begin the season without a shortstop due to injury — just not the one everyone expected. Backup Brendan Ryan, not the retiring Derek Jeter, is dealing with an upper-back injury that could postpone the start of his season.

Ryan was scratched from the Yankees lineup Thursday night 30 minutes before first pitch, when he felt a pinch in the back. Friday, he underwent tests for the back, which showed “something is pinching on a nerve.”

Ryan was visibly uncomfortable rotating his torso in the Yankees clubhouse and revealed he could feel the pain, which he described as an “electrical feeling in there,” when he breathes. He was annoyed.

“It’s frustrating,” Ryan said.

The setback prolongs a disheartening spring for Ryan. The slick-fielding shortstop, who signed a two-year, $5 million deal over the offseason, had not played since March 4 due a lower-back injury. He was cleared to play for the first time Thursday and was in the lineup until he irritated the back playing catch. Ryan emphasized the two injuries are not related.

As a result, Ryan, owner of a .619 career OPS, has been limited to nine plate appearances in four games this spring. He admitted even if he were cleared to play in minor-league games Monday, which is the best-case scenario, he may not have enough time to accumulate the necessary at-bats anyway.

“I just need to get to that point where I’m comfortable recognizing pitches and not costing the team with an automatic out,” Ryan, 31, said.

This is not Ryan’s first encounter with upper-back pain. He was diagnosed with a herniated disk in 2011 with the Mariners. The injury ended his season, but he was not placed on the disabled list because there were only a couple weeks remaining in the campaign.

Ryan insisted the injuries are not identical — he said his current ailment is less painful — though they are in the same area.

In 2011, he was administered an epidural for the affected area. This time, doctors elected to prescribe pills to quell the swelling and knots, but Ryan indicated he would also get a cortisone shot.

“I imagine we’ll go into it slowly again once it frees up, but it certainly isn’t like a couple years ago when I was really hurting,” Ryan said. “I just have to let it calm down.”

Without Ryan available to begin the season, the Yankees would choose two backup infielders from the threesome of Yangervis Solarte and Dean Anna, two career minor leaguers, and Eduardo Nuñez. The Yankees are confident the three utilitymen can play shortstop.

“I think right now, as long as we stay healthy, all the answers are here in camp,” Yankees general manager Brian Cashman said. “My job is to find somebody better than what we already have if at all possible. That never changes. But if he can’t go we have someone here who will be able to do that.”

Yankees manager Joe Girardi said Ryan’s status will not impact Derek Jeter’s playing time and he does not anticipate Jeter playing the Yankees’ first 13 games, which will be played over 13 consecutive days.

“I have told Derek all along, there is no magic number,” Girardi said. “It depends on how I feel that he’s moving and our communication; if he feels he needs a day. That’s how I’ll look at it.”

For now, it appears as though Jeter will begin his farewell tour in Houston without his backup.

“Things happen,” Ryan said. “It could be better, but it could be worse.”